Attachment for dental dams.



No. 628,487. Patented July ll, I899.

M. 0. NELSON.

ATTACHMENT FOR DENTAL DAMS.

(Application filed Nov. 14, 1898.)

{No Model.)

WITNEIEEEEI INVEN-TEIR UNITED STATES PATENT OFFICE.

MARTIN O. NELSON, OF NATICK, MASSACHUSETTS.

ATTACH MENT FOR DENTAL DAMS.

SPECIFICATION forming part of Letters Patent NO. 628,487, dated July 1 1, 1899. Application filed November 14, 1898. Serial No. 696,335. (No model.)

To all whom it may concern.-

Be it known that I, MARTIN O. NELSON, a citizen of the United States, residing in Natick, in the county of Middlese-X and State of Massachusetts, haveiuvented a new and Improved AttachinentforDental Dams,of-which the following is aspecification.

This is a device adapted to be attached to and suspended from the sheet of rubber or analogous material known in dentistry as a dam, and intended to prevent moisture from getting into the cavity or upon the tooth, which is being operated upon by the dentist.

The object of the device is to catch and receive scraps. of gold filling, which drop from the tooth while the dentist is operating upon it and which would be otherwiselost or would only be saved by a careful subsequent examination of the sweepings of the office.

The nature of the invention is fully described below and illustrated in the accompanying drawings, in which Figure 1 represents my device properly secured to a rubber dam which has been applied to a tooth which is to be operated upon by the dentist. Fig. 2 is a top View or plan of the device attached to the dam, a small portion. being represented as broken out. Fig. 3 is an end view of the device attached to the dam. Fig. 4 is a central cross vertical section of the same.

Similar letters of reference indicate corre sponding parts.

A represents an ordinary rubber dam through which the tooth to be operated upon has been thrust and from which ithangs;

The receptacle which is adapted to catch the gold scraps falling from the tooth comprises a back piece B with its lower edge formed up into the flap or lip O and with its upper edge folded over into the horizontal pocket D. The flap or lip 0 extends up in front of the back piece B, and the portion E extends down behind said back piece and is cemented or otherwise adhesively secured thereto, or is made integral at its lower edge therewith in order to form said pocket D.

The parts B, O, D, and E are preferably made of an integral piece of rubber, and the lower edge is preferably curved, as shown in Fig. 1, the lip 0 extending well up at the sides, so as to prevent any scraps from falling outside the receptacle. Within the pocket 'Dis laid a bar or plate F, of metal or other rigid material, said bar being strengthened and provided with a groove on its front surface by means of a longitudinal corrugation F. This prevents the receptacle from dragging down at the sides and preserves its form. The barFextends entirelythrough the pocket D and is provided at one end with a hinge H, to the pintle of which a rod or pin K is secured and thereby adapted to swing horizontally. opposite or coincident with the groove in the front surface of the plate F formed by the corrugation F and extends entirely across the front of said pocket. At the opposite end of the pocket a pair of jaws L is placed, said jaws consistingof a piece of metal whose central portion lies between the rear wall E of the pocket and whose two jaws or prongs extend through the stiffening-plate F above andv below the groove therein and are bent, as shown, to-receive and lock in position the free end of the swinging rod K.

To apply the device, the upper'portion is laid behind thelower edge of the dam and the rod K swung back against the front por tion of the said dam and caught in the catch L, as indicated in the drawings. In this po sition the rod or pin K presses the rubber into the groove formed by the corrugation F and thus holds the dam securely. When in such position, any scraps of gold or other material which fall down over the dam drop into This rod is so located as to be exactly the spacebehind the flap or lip C. After the i operation upon the tooth is finished the de- .vice is detached from the dam by swinging back the rod K, and the contents of the receptacle can be removed.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is- V The herein-described attachment for dental dams, comprising the receptacle consist ing of the back piece B, flap or lip O extending upward from the front surface of said 7 pocket; and mechanism for lockingthe free back piece, and pocket D; the bar or stiffthe bar, said locking rod or pin being oppoener F Within said pocket and provided W h site or coincident with said groove, substana horizontal groove on its front surface; the tially as described fastening rod or pin K hinged to one end of l said bar and adapted to swing in front of the MARTIN O. NELSON. Witnesses:

HENRY W. WILLIAMS,

A. N. BoNNEY.

end of the rod or pin to the opposite end of 

